Dithiino-tetracarboximides as such are already known. It is also known, that these compounds can be used as anthelmintics and insecticides (cf. U.S. Pat. No. 3,364,229). Furthermore the fungicidal use of such dithiino-tetracarboximides is known (WO 2010/043319).
Combinations of biological control agents, in particular of spore-forming bacteria with proven agricultural benefit and yeasts, with insecticides and certain fungicides are already known as well (WO 2009/124707, WO 2010/149369, WO 2010/149370).
Nematodes are microscopic unsegmented worms known to reside in virtually every type of environment (terrestrial, freshwater, marine). Of the over 80,000 known species many are agriculturally significant, particularly those classified as pests. One such species is the root knot nematode which attacks a broad range of plants, shrubs and crops. These soil-born nematodes attack newly formed roots causing stunted growth, swelling or gall formation. The roots may then crack open thus exposing the roots to other microorganisms such as bacteria or fungi. With environmentally friendly practices such as reduced or no tillage farming, and various nematode species acquiring resistance to transgenic seed, nematode related crop losses appear to be on the rise.
Chemical nematicides such as soil fumigants or non-fumigants have been in use for many years to combat nematode infestations. Such nematicides may require repeated applications of synthetic chemicals to the ground prior to planting. Due to their toxicity, chemical nematicides have come under scrutiny from the Environmental Protection Agency (EPA) and in some cases their use has been limited or restricted by the EPA. As the use of traditional chemical nematicides such as methyl-bromide and organophosphates continue to be phased out, a need for the development of alternative treatment options has arisen.
Along with ever increasing crop losses caused by parasitic nematodes, there are also many such losses which can alternatively be attributed to pathogenic fungal diseases. In addition to modifications of existing chemistries and the development of new efficacious compounds or combination of chemistries, the development and use of biological fungicides are being researched.
As nematicidal bacteria are not always completely effective as stand alone products, fungicidal bacteria tend to work better as a compliment rather than a replacement to traditional chemistries. U.S. Pat. No. 5,215,747 describes compositions composed of Bacillus subtilis (a biological fungicide) and chemical fungicides to increase the overall protection from phytopathenogenic fungal species.
The yeast Metschnikowia fructicola, in particular the strain NRRL Y-30752, is known (U.S. Pat. No. 6,994,849). This yeast provides a good protection of plants and plant parts against plant pathogenic fungi. However, the performance of such yeast is still not fully satisfactory under conditions of severe disease pressure.
Since the environmental and economic requirements imposed on modern-day crop protection compositions are continually increasing, with regard, for example, to the spectrum of action, toxicity, selectivity, application rate, formation of residues, and favourable preparation ability, and since, furthermore, there may be problems, for example, with resistances, a constant task is to develop new compositions, in particular fungicidal agents, which in some areas at least help to fulfil the abovementioned requirements.